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Mitz CA, Viloria-Petit AM. Contrasting effects of transforming growth factor β1 on programmed cell death of bovine mammary epithelial cell lines MAC-T and BME-UV1. J Dairy Sci 2020; 103:5532-5549. [PMID: 32229120 DOI: 10.3168/jds.2019-17460] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Accepted: 01/17/2020] [Indexed: 11/19/2022]
Abstract
A previous study in the bovine mammary epithelial cell line BME-UV1 demonstrated that suppression of the phosphatidylinositol-4,5-biphosphate 3 kinase (PI3K)/AKT (somatotropic) signaling pathway was required for transforming growth factor β1 (TGFβ1)-induced programmed cell death (PCD). To investigate whether this is a universal mechanism for TGFβ1 to induce PCD in bovine mammary epithelium, we compared TGFβ1 modulation of PI3K/AKT and its role in PCD in 2 bovine mammary epithelial cell lines: MAC-T and BME-UV1. In MAC-T cells, TGFβ1 promoted cell survival, and this paralleled a reduction in PI3K/AKT activity, rather than an increase. In BME-UV1 cells, TGFβ1 induced PCD, and this was accompanied by a time-dependent effect on PI3K/AKT activity, including an initial significant increase in the phosphorylation of AKT at 3 h, followed by a reduction between 12 and 24 h, and then an increase at 48 h. Inhibition of AKT activity enhanced TGFβ1-induced PCD in BME-UV1 cells but had no effect on MAC-T cells, suggesting that TGFβ1 mediates PCD in BME-UV1 cells through suppression of AKT activity. Inhibition of TGFβ receptor type I (TβRI) kinase activity completely abrogated TGFβ1-induced PCD in BME-UV1 cells but had no effect on TGFβ1-induced suppression of PCD in MAC-T cells, demonstrating that TGFβ1-induced PCD in BME-UV1 cells is dependent on TβRI/SMAD signaling. These and previous observations suggest that the different effects of TGFβ1 on PCD in these cell lines might involve noncanonical signaling pathways other than PI3K/AKT, and may reflect their different lineages. Future studies should address this finding, taking into consideration the effect that different culture conditions might have on cell phenotype.
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Affiliation(s)
- C A Mitz
- Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, 50 Stone Road East, Guelph, ON, N1G 2W1, Canada
| | - A M Viloria-Petit
- Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, 50 Stone Road East, Guelph, ON, N1G 2W1, Canada.
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Mitz CA, Viloria-Petit AM. TGF-beta signalling in bovine mammary gland involution and a comparative assessment of MAC-T and BME-UV1 cells as in vitro models for its study. PeerJ 2019; 6:e6210. [PMID: 30671288 PMCID: PMC6338098 DOI: 10.7717/peerj.6210] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Accepted: 12/04/2018] [Indexed: 12/12/2022] Open
Abstract
The goal of the dairy industry is ultimately to increase lactation persistency, which is the length of time during which peak milk yield is sustained. Lactation persistency is determined by the balance of cell apoptosis and cell proliferation; when the balance is skewed toward the latter, this results in greater persistency. Thus, we can potentially increase milk production in dairy cows through manipulating apoptogenic and antiproliferative cellular signaling that occurs in the bovine mammary gland. Transforming growth factor beta 1 (TGFβ1) is an antiproliferative and apoptogenic cytokine that is upregulated during bovine mammary gland involution. Here, we discuss possible applications of TGFβ1 signaling for the purposes of increasing lactation persistency. We also compare the features of mammary alveolar cells expressing SV-40 large T antigen (MAC-T) and bovine mammary epithelial cells-clone UV1 (BME-UV1) cells, two extensively used bovine mammary epithelial cell lines, to assess their appropriateness for the study of TGFβ1 signaling. TGFβ1 induces apoptosis and arrests cell growth in BME-UV1 cells, and this was reported to involve suppression of the somatotropic axis. Conversely, there is no proof that exogenous TGFβ1 induces apoptosis of MAC-T cells. In addition to TGFβ1's different effects on apoptosis in these cell lines, hormones and growth factors have distinct effects on TGFβ1 secretion and synthesis in MAC-T and BME-UV1 cells as well. MAC-T and BME-UV1 cells may behave differently in response to TGFβ1 due to their contrasting phenotypes; MAC-T cells have a profile indicative of both myoepithelial and luminal populations, while the BME-UV1 cells exclusively contain a luminal-like profile. Depending on the nature of the research question, the use of these cell lines as models to study TGFβ1 signaling should be carefully tailored to the questions asked.
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Affiliation(s)
- Charlotte Alexandra Mitz
- Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Guelph, ON, Canada
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Ellman MB, Kim J, An HS, Chen D, Kc R, Li X, Xiao G, Yan D, Suh J, van Wijnen AJ, Wang JHC, Kim SG, Im HJ. Lactoferricin enhances BMP7-stimulated anabolic pathways in intervertebral disc cells. Gene 2013; 524:282-91. [PMID: 23644135 PMCID: PMC3679319 DOI: 10.1016/j.gene.2013.04.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2013] [Revised: 04/01/2013] [Accepted: 04/03/2013] [Indexed: 01/07/2023]
Abstract
Bone-morphogenetic protein-7 (BMP7) is a well-known anabolic and anti-catabolic growth factor on intervertebral disc (IVD) matrix and cell homeostasis. Similarly, Lactoferricin B (LfcinB) has recently been shown to have pro-anabolic, anti-catabolic, anti-oxidative and/or anti-inflammatory effects in bovine disc cells in vitro. In this study, we investigated the potential benefits of using combined peptide therapy with LfcinB and BMP7 for intervertebral disc matrix repair and to understand cellular and signaling mechanisms controlled by these factors. We studied the effects of BMP7 and LfcinB as individual treatments and combined therapy on bovine nucleus pulposus (NP) cells by assessing proteoglycan (PG) accumulation and synthesis, and the gene expression of matrix protein aggrecan and transcription factor SOX-9. We also analyzed the role of Noggin, a BMP antagonist, in IVD tissue and examined its effect after stimulation with LfcinB. To understand the molecular mechanisms by which LfcinB synergizes with BMP7, we investigated the ERK-SP1 axis as a downstream intracellular signaling regulator involved in BMP7 and LfcinB-mediated activities. Treatment of bovine NP cells cultured in alginate with LfcinB plus BMP7 synergistically stimulates PG synthesis and accumulation in part by upregulation of aggrecan gene expression. The synergism results from LfcinB-mediated activation of Sp1 and SMAD signaling pathways by (i) phosphorylation of SMAD 1/5/8; (ii) downregulation of SMAD inhibitory factors [i.e., noggin and SMAD6 (inhibitory SMAD)]; and (iii) upregulation of SMAD4 (universal co-SMAD). These data indicate that LfcinB-suppression of Noggin may eliminate the negative feedback of BMP7, thereby maximizing biological activity of BMP7 and ultimately shifting homeostasis to a pro-anabolic state in disc cells. We propose that combination growth factor therapy using BMP7 and LfcinB may be beneficial for treatment of disc degeneration.
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Affiliation(s)
- Michael B Ellman
- Department of Biochemistry, Rush University Medical Center, Chicago, IL 60612
- Department of Orthopedic Surgery, Rush University Medical Center, Chicago, IL 60612
| | - Jaesung Kim
- Department of Biochemistry, Rush University Medical Center, Chicago, IL 60612
| | - Howard S An
- Department of Orthopedic Surgery, Rush University Medical Center, Chicago, IL 60612
| | - Di Chen
- Department of Biochemistry, Rush University Medical Center, Chicago, IL 60612
| | - Ranjan Kc
- Department of Biochemistry, Rush University Medical Center, Chicago, IL 60612
| | - Xin Li
- Department of Biochemistry, Rush University Medical Center, Chicago, IL 60612
| | - Guozhi Xiao
- Department of Biochemistry, Rush University Medical Center, Chicago, IL 60612
| | - Dongyao Yan
- Department of Biochemistry, Rush University Medical Center, Chicago, IL 60612
| | - Joon Suh
- Department of Biochemistry, Rush University Medical Center, Chicago, IL 60612
| | - Andre J. van Wijnen
- Center of Regenerative Medicine and Departments of Orthopedic Surgery & Biochemistry & Molecular Biology, Mayo Clinic, Rochester, MN 55905
| | - James H-C Wang
- MechanoBiology Laboratory, Departments of Orthopedic Surgery and Bioengineering, University of Pittsburgh, PA 15213, USA
| | - Su-Gwan Kim
- Department of Oral and Maxillofacial Surgery, School of Dentistry, Chosun University, GwangJu City, Republic of Korea, 501-759
| | - Hee-Jeong Im
- Department of Biochemistry, Rush University Medical Center, Chicago, IL 60612
- Department of Orthopedic Surgery, Rush University Medical Center, Chicago, IL 60612
- Department of Internal Medicine, Section of Rheumatology, Rush University Medical Center, Chicago, IL 60612
- Department of Bioengineering, University of Illinois at Chicago, IL 60612
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Teplova I, Lozy F, Price S, Singh S, Barnard N, Cardiff RD, Birge RB, Karantza V. ATG proteins mediate efferocytosis and suppress inflammation in mammary involution. Autophagy 2013; 9:459-75. [PMID: 23380905 PMCID: PMC3627664 DOI: 10.4161/auto.23164] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Involution is the process of post-lactational mammary gland regression to quiescence and it involves secretory epithelial cell death, stroma remodeling and gland repopulation by adipocytes. Though reportedly accompanying apoptosis, the role of autophagy in involution has not yet been determined. We now report that autophagy-related (ATG) proteins mediate dead cell clearance and suppress inflammation during mammary involution. In vivo, Becn1+/− and Atg7-deficient mammary epithelial cells (MECs) produced ‘competent’ apoptotic bodies, but were defective phagocytes in association with reduced expression of the MERTK and ITGB5 receptors, thus pointing to defective apoptotic body engulfment. Atg-deficient tissues exhibited higher levels of involution-associated inflammation, which could be indicative of a tumor-modulating microenvironment, and developed ductal ectasia, a manifestation of deregulated post-involution gland remodeling. In vitro, ATG (BECN1 or ATG7) knockdown compromised MEC-mediated apoptotic body clearance in association with decreased RAC1 activation, thus confirming that, in addition to the defective phagocytic processing reported by other studies, ATG protein defects also impair dead cell engulfment.
Using two different mouse models with mammary gland-associated Atg deficiencies, our studies shed light on the essential role of ATG proteins in MEC-mediated efferocytosis during mammary involution and provide novel insights into this important developmental process. This work also raises the possibility that a regulatory feedback loop exists, by which the efficacy of phagocytic cargo processing in turn regulates the rate of engulfment and ultimately determines the kinetics of phagocytosis and dead cell clearance.
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Affiliation(s)
- Irina Teplova
- University of Medicine and Dentistry of New Jersey, Robert Wood Johnson Medical School, Piscataway, NJ, USA
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Kim JS, Ellman MB, An HS, van Wijnen AJ, Borgia JA, Im HJ. Insulin-like growth factor 1 synergizes with bone morphogenetic protein 7-mediated anabolism in bovine intervertebral disc cells. ACTA ACUST UNITED AC 2011; 62:3706-15. [PMID: 20812336 DOI: 10.1002/art.27733] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
OBJECTIVE We undertook this study to assess the therapeutic benefits of intervertebral disc matrix repair and regeneration by evaluating the potential synergistic effect of insulin-like growth factor 1 (IGF-1) and bone morphogenetic protein 7 (BMP-7) on bovine spine discs and by elucidating the relevant molecular/cellular mechanisms. METHODS Bovine nucleus pulposus (NP) cells were treated with BMP-7 and IGF-1. The subsequent anabolic effects driven by NP cells were assessed for proteoglycan (PG) synthesis by (35) S-sulfate incorporation and for PG accumulation by dimethylmethylene blue assays. Matrix formation was visualized by particle exclusion assay. Key matrix components and transcription factors were analyzed by real-time reverse transcription-polymerase chain reaction to determine the signaling pathways by which IGF-1 suppresses noggin, a potent inhibitor of BMP-7. Western blotting and nuclear translocation experiments were performed to assess the activation of Smad proteins. RESULTS Stimulation of bovine NP cells by both IGF-1 and BMP-7 greatly potentiated anabolism through complementary and synergistic mechanisms on matrix formation compared with treatment with either growth factor alone. The exogenously added decoy ligand, noggin, attenuated the anabolic effects of BMP-7, and noggin was substantially increased by BMP-7, suggesting a negative feedback regulatory mechanism. In contrast, IGF-1 significantly suppressed noggin expression via the phosphatidylinositol 3-kinase/Akt pathway and thus potentiated BMP-7 signaling in bovine NP cells. Upon combination treatment, IGF-1 activated Smad2, while BMP-7 activated Smad1/5/8 and Smad3, thus inducing all Smad signaling pathways and mimicking the effects of the combination of transforming growth factor β and BMP-7 CONCLUSION Combination growth factor therapy using BMP-7 and IGF-1 may have considerable promise in the treatment of spine disc degeneration.
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Affiliation(s)
- Jae-Sung Kim
- Rush University Medical Center, Chicago, Illinois, USA
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Tarantino G, Savastano S, Colao A. Hepatic steatosis, low-grade chronic inflammation and hormone/growth factor/adipokine imbalance. World J Gastroenterol 2010; 16:4773-83. [PMID: 20939105 PMCID: PMC2955246 DOI: 10.3748/wjg.v16.i38.4773] [Citation(s) in RCA: 152] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Non-alcoholic fatty liver disease (NAFLD), a further expression of metabolic syndrome, strictly linked to obesity and diabetes mellitus, is characterized by insulin resistance (IR), elevated serum levels of free fatty acids and fatty infiltration of the liver, which is known as hepatic steatosis. Hepatocyte apoptosis is a key feature of this disease and correlates with its severity. Free-fatty-acid-induced toxicity represents one of mechanisms for the pathogenesis of NAFLD and hormones, growth factors and adipokines influence also play a key role. This review highlights the various pathways that contribute to the development of hepatic steatosis. Circulating concentrations of inflammatory cytokines are reckoned to be the most important factor in causing and maintaining IR. Low-grade chronic inflammation is fundamental in the progression of NAFLD toward higher risk cirrhotic states.
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De Vries LD, Dover H, Casey T, VandeHaar MJ, Plaut K. Characterization of mammary stromal remodeling during the dry period. J Dairy Sci 2010; 93:2433-43. [PMID: 20494151 DOI: 10.3168/jds.2009-2764] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2009] [Accepted: 02/09/2010] [Indexed: 11/19/2022]
Abstract
During the dry period between successive lactations, the mammary gland of dairy cows undergoes extensive remodeling that is marked by phases of involution and mammogenesis. Changes in the mammary epithelium during the dry period have been well characterized; however, few studies have examined the changes that occur in stromal tissue. The objective of this study was to characterize changes that occur in mammary stroma during the dry period. Mammary biopsies were taken from 9 multigravid Holstein cows in late lactation, at 1 wk after dry-off, 3 wk before expected calving date, and 1 wk before expected calving date. Tissue was fixed in formalin, embedded in paraffin, and cut into 5-mum sections. Sections were stained with hematoxylin and eosin or with immunohistochemistry for expression of smooth muscle alpha actin (SMA), fibronectin, stromelysin-1 (MMP-3), transforming growth factor-beta1 (TGF-beta1), and TGF-beta receptor 2 (TGF-betaR2). Images of tissues were captured with light microscopy, and imaging software was used to measure intralobular stromal area, number of activated fibroblasts, as identified by expression of SMA, and percentage of intralobular stromal area expressing fibronectin, MMP3, TGF-beta1, and TGF-betaR2. Analyses of variance were conducted and statistical differences were based on the least squares means of biopsy stage. Number of activated fibroblasts was greater at 1 wk dry than at 1 wk before calving (2,720 vs. 1,800 cells/mm(2)), percentage intralobular stromal area was greater at 1 wk dry (32%) and 3 wk before calving (37%) than at 1 wk before calving (25%), and TGF-beta1 expression decreased 15% from late lactation to the dry period. The percentages of stromal area expressing fibronectin, MMP-3, and TGF-betaR2 and the percentage of myofibroblasts were not different across biopsy stages. These results support the concept that stromal expression of transforming growth factor-beta1 and fibroblast proliferation may be important for remodeling during the dry period.
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Affiliation(s)
- L D De Vries
- Department of Animal Science, Michigan State University, East Lansing 48824-1225, USA
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Tsuchiya M, Sharma R, Tye CE, Sugiyama T, Bartlett JD. Transforming growth factor-beta1 expression is up-regulated in maturation-stage enamel organ and may induce ameloblast apoptosis. Eur J Oral Sci 2009; 117:105-12. [PMID: 19320718 DOI: 10.1111/j.1600-0722.2009.00612.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Transforming growth factor-beta1 (TGF-beta1) regulates a variety of cellular responses that are dependent on the developmental stage and on the origins of the cell or the tissue. In mature tissues, and especially in tissues of epithelial origin, TGF-beta1 is generally considered to be a growth inhibitor that may also promote apoptosis. The ameloblast cells of the enamel organ epithelium are adjacent to and responsible for the developing enamel layer on unerupted teeth. Once the enamel layer reaches its full thickness, the tall columnar secretory-stage ameloblasts shorten, and a portion of these maturation-stage ameloblasts become apoptotic. Here we investigate whether TGF-beta1 plays a role in apoptosis of the maturation-stage ameloblasts. We demonstrate in vitro that ameloblast lineage cells are highly susceptible to TGF-beta1-mediated growth arrest and are prone to TGF-beta1-mediated cell death/apoptosis. We also demonstrate in vivo that TGF-beta1 is expressed in the maturation-stage enamel organ at significantly higher levels than in the earlier secretory-stage enamel organ. This increased expression of TGF-beta1 correlates with an increase in expression of the enamel organ immediate-early stress-response gene and with a decrease in the anti-apoptotic Bcl2 : Bax expression ratio. We conclude that TGF-beta1 may play an important role in ameloblast apoptosis during the maturation stage of enamel development.
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Affiliation(s)
- Masahiro Tsuchiya
- Department of Cytokine Biology, Forsyth Institute, Harvard School of Dental Medicine, Boston, MA 02115, USA
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Romorini L, Coso OA, Pecci A. Bcl-XL mediates epidermal growth factor dependent cell survival in HC11 mammary epithelial cells. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2009; 1793:496-505. [DOI: 10.1016/j.bbamcr.2008.12.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2008] [Revised: 11/18/2008] [Accepted: 12/02/2008] [Indexed: 10/21/2022]
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Durai R, Yang SY, Sales KM, Seifalian AM, Goldspink G, Winslet MC. Increased apoptosis and decreased proliferation of colorectal cancer cells using insulin-like growth factor binding protein-4 gene delivered locally by gene transfer. Colorectal Dis 2007; 9:625-31. [PMID: 17824980 DOI: 10.1111/j.1463-1318.2006.01190.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
OBJECTIVE Insulin-like growth factor (IGF)-I induces proliferation of transformed cells. Its binding proteins (IGFBP) are involved in local regulation of IGF. This study assessed the effects of overexpression of IGFBP-4 on the development of cancer in vivo. METHOD Nude mice were subcutaneously inoculated with HT-29 colorectal cancer cells (3 x 10(6)). When the tumour became visible (1 week after inoculation), animals received either 150 microg of mammalian expression vector containing IGFBP-4 cDNA or vector alone (n = 6 each) by peritumoural injection. Tumour size was measured during the growth. After 3 weeks of IGFBP-4 induction, animals were killed and tumour tissue samples were collected for examining the level of IGFBP-4 expression. Tumour mitotic activities were determined by counting numbers of mitotic cells on the tissue section. Apoptosis was investigated by terminal deoxynucleotidyl transferase-mediated dUDP nick end labelling assay. RESULTS Following IGFBP-4 treatment, tumour showed large necrotic areas, significantly increased numbers of apoptotic cells (36.67 +/- 7.36 vs 7.07 +/- 1.91, P < 0.01 vs control), decreased cells undergoing mitosis (2.31 +/- 0.32 vs 3.61 +/- 0.27, P < 0.01 vs control) and higher expression of IGFBP-4 (P < 0.05 vs control). CONCLUSION IGFBP-4 gene transfer increased apoptosis and decreased mitosis, but tumour volume was not significantly altered possibly due to cellular debris filling the centre of tumours.
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Affiliation(s)
- R Durai
- Academic Division of Surgical and Interventional Sciences, University College London, Hampstead Campus, Royal Free Hampstead NHS Trust Hospital, London, UK
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Jemal A, Siegel R, Ward E, Murray T, Xu J, Thun MJ. Cancer statistics, 2007. CA Cancer J Clin 2007; 1785:156-81. [PMID: 17237035 DOI: 10.1016/j.bbcan.2007.12.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2007] [Revised: 12/02/2007] [Accepted: 12/03/2007] [Indexed: 02/06/2023] Open
Abstract
Each year, the American Cancer Society (ACS) estimates the number of new cancer cases and deaths expected in the United States in the current year and compiles the most recent data on cancer incidence, mortality, and survival based on incidence data from the National Cancer Institute, Centers for Disease Control and Prevention, and the North American Association of Central Cancer Registries and mortality data from the National Center for Health Statistics. This report considers incidence data through 2003 and mortality data through 2004. Incidence and death rates are age-standardized to the 2000 US standard million population. A total of 1,444,920 new cancer cases and 559,650 deaths for cancers are projected to occur in the United States in 2007. Notable trends in cancer incidence and mortality rates include stabilization of the age-standardized, delay-adjusted incidence rates for all cancers combined in men from 1995 through 2003; a continuing increase in the incidence rate by 0.3% per year in women; and a 13.6% total decrease in age-standardized cancer death rates among men and women combined between 1991 and 2004. This report also examines cancer incidence, mortality, and survival by site, sex, race/ethnicity, geographic area, and calendar year, as well as the proportionate contribution of selected sites to the overall trends. While the absolute number of cancer deaths decreased for the second consecutive year in the United States (by more than 3,000 from 2003 to 2004) and much progress has been made in reducing mortality rates and improving survival, cancer still accounts for more deaths than heart disease in persons under age 85 years. Further progress can be accelerated by supporting new discoveries and by applying existing cancer control knowledge across all segments of the population.
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Affiliation(s)
- Ahmedin Jemal
- Cancer Occurrence, Department of Epidemiology and Surveillance Research, American Cancer Society, Atlanta, GA, USA
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Quesnell RR, Han X, Schultz BD. Glucocorticoids stimulate ENaC upregulation in bovine mammary epithelium. Am J Physiol Cell Physiol 2007; 292:C1739-45. [PMID: 17251323 DOI: 10.1152/ajpcell.00369.2006] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Mammary epithelia produce an isotonic, low-Na(+) fluid that is rich in nutrients. Mechanisms that account for the low electrolyte concentration have not been elucidated, although amiloride-sensitive ion transport has been reported in some situations. We hypothesized that corticosteroid exposure modulates epithelial Na(+) channel (ENaC) expression and/or activity in bovine mammary epithelial cells. BME-UV cells were grown to confluent monolayers on permeable supports with a standard basolateral medium and apical medium of low-electrolyte, high-lactose composition that resembles the ionic composition of milk. Ion transport was assessed in modified Ussing flux chambers. Exposure to glucocorticoids (dexamethasone, cortisol, or prednisolone), but not aldosterone, increased short-circuit current (I(sc)), a sensitive measure of net ion transport, whereas apical exposure to amiloride or benzamil reduced corticosteroid-induced I(sc) close to basal levels. Quantitative RT-PCR indicated a glucocorticoid-induced increase in mRNA for beta- and gamma-ENaC, whereas alpha-ENaC mRNA expression was only mildly affected. Exposure to mifepristone (a glucocorticoid receptor antagonist), but not spironolactone (a mineralocorticoid receptor antagonist), precluded both the corticosteroid-induced elevation in amiloride-sensitive I(sc) and the induced changes in beta- and gamma-ENaC mRNA. We conclude that Na(+) movement across mammary epithelia is modulated by corticosteroids via a glucocorticoid receptor-mediated mechanism that regulates the expression of the beta- and gamma-subunits of ENaC. ENaC expression and activity could account for the low Na(+) concentration that is typical of milk.
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Affiliation(s)
- Rebecca R Quesnell
- Department of Anatomy and Physiology, 228 Coles Hall, Kansas State University, Manhattan, KS 66506, USA
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Kang HR, Cho SJ, Lee CG, Homer RJ, Elias JA. Transforming growth factor (TGF)-beta1 stimulates pulmonary fibrosis and inflammation via a Bax-dependent, bid-activated pathway that involves matrix metalloproteinase-12. J Biol Chem 2007; 282:7723-32. [PMID: 17209037 DOI: 10.1074/jbc.m610764200] [Citation(s) in RCA: 144] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Fibrosis, apoptosis, and the exaggerated production of transforming growth factor (TGF)-beta(1) are juxtaposed in a variety of pulmonary diseases including the interstitial lung diseases and asthma. In these disorders, the relationships between these responses are not well defined. In addition, the apoptosis pathways that contribute to these responses and the mechanism(s) of their contribution have not been described. We hypothesized that BH3 domain-only protein-induced apoptosis plays an important role in the pathogenesis of TGF-beta(1)-induced pulmonary responses. To test this hypothesis, we characterized the effects of transgenic TGF-beta(1) in mice with wild type (WT) and null Bax loci. To investigate the mechanisms of Bax activation and its effector functions, we also compared the effects of TGF-beta(1) in mice with WT and null Bid and matrix metalloproteinase (MMP)-12 loci, respectively. These studies demonstrate that TGF-beta(1) is a potent stimulator of Bax, Bid, and MMP-12. The studies also demonstrate that Bax and Bid play key roles in the pathogenesis of TGF-beta(1)-induced inflammation, fibrosis, and apoptosis; that TGF-beta(1) stimulates MMP-12, TIMP-1, and cathepsins and inhibits MMP-9 and p21 via Bax- and Bid-dependent mechanisms; and that TGF-beta(1)-stimulated pulmonary fibrosis is ameliorated in MMP-12-deficient animals. Finally, they demonstrate that Bax, Bid, and MMP-12 play similar roles in bleomycin-induced fibrosis, thereby highlighting the importance of this Bid-activated, Bax-mediated pathway and downstream MMP-12 in a variety of fibrogenic settings.
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Affiliation(s)
- Hye-Ryun Kang
- Section of Pulmonary and Critical Care Medicine, Yale University School of Medicine, New Haven, Connecticut 06520, USA
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Quesnell RR, Erickson J, Schultz BD. Apical electrolyte concentration modulates barrier function and tight junction protein localization in bovine mammary epithelium. Am J Physiol Cell Physiol 2007; 292:C305-18. [PMID: 16885391 DOI: 10.1152/ajpcell.00567.2005] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In vitro mammary epithelial cell models typically fail to form a consistently tight barrier that can effectively separate blood from milk. Our hypothesis was that mammary epithelial barrier function would be affected by changes in luminal ion concentration and inflammatory cytokines. Bovine mammary epithelial (BME-UV cell line) cells were grown to confluence on permeable supports with a standard basolateral medium and either high-electrolyte (H-elec) or low-electrolyte (L-elec) apical medium for 14 days. Apical media were changed to/from H-elec medium at predetermined times prior to assay. Transepithelial electrical resistance ( Rte) was highest in monolayers continuously exposed to apical L-elec. A time-dependent decline in Rtebegan within 24 h of H-elec medium exposure. Change from H-elec medium to L-elec medium time-dependently increased Rte. Permeation by FITC-conjugated dextran was elevated across monolayers exposed to H-elec, suggesting compromise of a paracellular pathway. Significant alteration in occludin distribution was evident, concomitant with the changes in Rte, although total occludin was unchanged. Neither substitution of Na+with N-methyl-d-glucosamine (NMDG+) nor pharmacological inhibition of transcellular Na+transport pathways abrogated the effects of apical H-elec medium on Rte. Tumor necrosis factor alpha, but not interleukin-1β nor interleukin-6, in the apical compartment caused a significant decrease in Rtewithin 8 h. These results indicate that mammary epithelium is a dynamic barrier whose cell-cell contacts are acutely modulated by cytokines and luminal electrolyte environment. Results not only demonstrate that BME-UV cells are a model system representative of mammary epithelium but also provide critical information that can be applied to other mammary model systems to improve their physiological relevance.
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Affiliation(s)
- Rebecca R Quesnell
- Department of Anatomy and Physiology, 228 Coles Hall, Kansas State University, Manhattan, KS 66506, USA
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15
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Reynolds AR, Kyprianou N. Growth factor signalling in prostatic growth: significance in tumour development and therapeutic targeting. Br J Pharmacol 2006; 147 Suppl 2:S144-52. [PMID: 16465179 PMCID: PMC1751493 DOI: 10.1038/sj.bjp.0706635] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
The intricate balance maintained between cell growth and proliferation factors and apoptosis-inducing factors is fundamental to the regulation of prostate growth. Disruptions in this homeostasis often trigger the loss of apoptosis and the over-expression of factors promoting cell survival and proliferation, inevitably leading to tumorigenesis and cancer. Deregulation of prostate growth during prostate cancer development and progression is characterized by apoptotic evasion, uncontrolled proliferation, and increased invasive potential. Thus, in advanced stages of disease progression, surviving prostate tumour cells acquire the ability to migrate and invade heterotopic tissues, with the bone and lymph nodes being the most common sites for human prostate cancer metastasis. The challenges in the implementation of effective therapeutic strategies for the treatment of advanced metastatic prostate cancer reflect the multidimensional nature and functional significance of antiapoptotic pathways in the emergence of therapeutic resistance of prostate tumours. In this chapter, we discuss the current understanding of the molecular mechanisms governing growth factor signalling pathways with often overlapping functions that contribute to loss of apoptosis control and activation of cell proliferation towards aggressive prostate tumorigenic growth and metastatic behaviour. While a full understanding of the prosurvival characteristics of these growth factor pathways is still evolving, the impact that growth factors such a epidermal growth factor and transforming growth factor-beta can be recognized by the vigorous attempts at therapeutic targeting of their key signalling steps.
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Affiliation(s)
- Arich Ryan Reynolds
- Department of Surgery, University of Kentucky Medical Center, Lexington, KY 40536, USA.
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16
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Burger AM, Leyland-Jones B, Banerjee K, Spyropoulos DD, Seth AK. Essential roles of IGFBP-3 and IGFBP-rP1 in breast cancer. Eur J Cancer 2005; 41:1515-27. [PMID: 15979304 DOI: 10.1016/j.ejca.2005.04.023] [Citation(s) in RCA: 109] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2005] [Revised: 04/11/2005] [Accepted: 04/18/2005] [Indexed: 11/29/2022]
Abstract
Insulin and insulin-like growth factors (IGFs) have critical functions in growth regulatory signalling pathways. They are part of a tightly controlled network of ligands, receptors, binding proteins and their proteases. However, the system becomes uncontrolled in neoplasia. The insulin-like growth factor binding protein 3 (IGFBP-3) and the insulin-like growth factor binding protein-related protein 1 (IGFBP-rP1) have unique properties among the sixteen known members of the IGFBP superfamily. IGFBP-3 has very high affinity for IGFs (k(d) approximately 10(-10) M), it transports >75% of serum IGF-I and -II, whereas it's affinity for insulin is very low. On the other hand, IGFBP-rP1 binds insulin with very high affinity (500-fold higher compared to other IGFBPs), but has low affinity for IGF-I and -II proteins (k(d) = 3 x 10(-8) M). In this review, we have examined the roles of IGFBP-3 and IGFBP-rP1 in breast cancer, and discuss the potential impact of these two proteins in mammary carcinoma risk assessment and the development of treatments for breast cancer.
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Affiliation(s)
- Angelika M Burger
- Laboratory of Molecular Pathology, Department of Anatomic Pathology and Division of Molecular and Cellular Biology, Sunnybrook and Women's College Health Sciences Centre, Toronto, Ont., Canada.
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